The Pioneer program is the name of a few unmannedspace missions done by NASA between 1958 and 1978. Problably the best-known of these probes were Pioneer 10 and 11, launched in 1972 and 1973 respectively.
Both carried a plaque as shown.
Pioneer 10, under construction in 1971. Pioneer 10 and 11 are the most famous probes in the Pioneer program. They were the first probes to visit the outer planets, and the first to go beyond the orbit of Pluto